Rotatable insert for aircraft seat base
A vibration-reducing insert is usable to reduce vibration or play between two metal aircraft components. The insert rotates on a fastener, and includes a shelf that projects into the gap and operates as an indexable cam to establish an appropriate compression in an engaged portion of the shelf.
1. A mounting system for a seat inside an aircraft, the aircraft having a first floor rail and a second floor rail, the first floor rail being spaced apart from the second floor rail, the mounting system comprising:
a first mount configured to follow and be mounted onto the first rail, an upper surface on the first mount including one or more upwardly-extending lugs, the lugs defining apertures therethrough;
a second mount being configured to follow and be mounted onto the second rail, an upper surface on the second mount including one or more upwardly-extending lugs, the lugs defining apertures therethrough;
a seat base configured to be secured onto and above the first and second mounts, the seat base including one or more downwardly-extending flanges, the one or more flanges including one or more apertures being alignable with the one or more apertures in the one or more lugs such that one or more bolts can be received through the flange and lug to secure the first and second mounts to the seat base;
each of the one or more bolts having a threaded end and a head, the head having a tool-receiving configuration; and
one or more inserts, each insert having:
an axially central bolt-receiving aperture;
a head-receiving side having a head-securing recess, the recess being configured to receive and secure the tool-receiving configuration of each bolt, thus causing each insert to rotate with each bolt;
an abutment side opposite the head-receiving side;
an outer edge of the insert comprising a substantially-arcuate shelf extending out from the abutment side of the insert, the arcuate shelf being configured to be rotatable inside a gap established between a lower end of each of the one or more downwardly-extending flanges on the seat base and an upper surface adjacent to each of the one or more lugs on the first and second mounts; and
the substantially-arcuate shelf having a plurality of varying thicknesses, each thickness in the plurality establishing a different compression level between the one or more lower ends of the flanges and the one on more upper surfaces adjacent to the flanges.
2. The mounting system of claim 1 wherein each of the one or more flanges are part of a clevis pair configured to sandwich each of the one or more lugs.
3. The mounting system of claim 1 wherein the first and second rail mounts are spaced apart and substantially parallel to one another.
4. The mounting system of claim 1 wherein each of the one or more inserts are constructed of a compressible material having a compressibility and a coefficient of friction configured to avoiding galling of engaged seat structures during use.
5. The mounting system of claim 4 wherein each of the one or more inserts are made of plastic.
6. The mounting system of claim 1 wherein the head-receiving recess is configured to only partially receive the bolt head leaving an exposed portion, the exposed portion enabling operation of the bolt by a tool.
7. The mounting system of claim 1 wherein each of the one or more bolt heads and each head-receiving recess have a hexagonal shape.
8. The mounting system of claim 1 wherein the substantially-arcuate shelf extending out from the abutment side of the insert functions as an indexed cam.
9. The mounting system of claim 1 wherein the substantially-arcuate shelf further comprises:
a plurality of consecutive radially-outcropped ramp faces, a first ramped face in the plurality being at a same angle relative to tangent as a second consecutive ramped surface in the plurality.
10. The mounting system of claim 9 wherein a first position of the first surface and a second position of the second surface establish two distinctive indexed levels of pressure created between a lower end of each of the one or more downwardly-extending flanges on the seat base and an upper surface adjacent to each of the one or more lugs on the first and second mounts.
11. The mounting system of claim 10 wherein an angle or the first surface and second surface taken relative to a tangent taken at a leading edge for the first and second surfaces are substantially the same.
12. A system for reducing vibration between a first aircraft component and a second aircraft component, the first and second components being connected using a fastener, the fastener having a head, the system comprising:
an insert configured to receive and secure the fastener head such that the insert rotates with the fastener;
a shelf extending outwardly from an edge of the insert, the shelf configured to be introduced into a gap created between a portion of the first component and a surface of the second component, the shelf also being outwardly ramped creating a plurality of thicknesses in a direction of rotation; and
the system being further configured such that a rotation of the fastener head results in engagement of a portion of the ramp having a greater thickness selectively increasing a pressure in the portion.
13. The system of claim 12 wherein the first aircraft component is a flange and the second aircraft component is a lug.
14. The system of claim 12 wherein the first aircraft component and the second aircraft component are both made of metal.
15. The system of claim 14 wherein the shelf on the insert is made of a compressible material having a compressibility and a coefficient of friction configured to avoiding galling of the first and second aircraft components.
16. The system of claim 15 wherein the shelf on the insert is made of plastic.
17. The system of claim 16 wherein the insert is made entirely of plastic.
18. The system of claim 12 wherein:
a first side of the insert includes a recess that is shaped to a shape of the fastener head to enable the insert to rotate with the fastener when the fastener is actuated.
19. The system of claim 18 wherein the recess is configured to only partially receive a bolt head leaving an exposed portion, the exposed portion enabling actuation of the bolt by a tool.
20. The system of claim 12 wherein the shelf includes a plurality of consecutive radially-outcropped ramp faces located at a plurality of different angular positions about a periphery of the insert, each ramped face, upon engagement inside the gap between the first and second components, resulting in an increase or decrease in compression to establish distinctive indexed compression levels based on a particular angular position of the insert.